1. Technical Field
The present invention relates to a light source device and display apparatus arranged so that light which is emitted from a light source section goes out through one surface of a light guide plate.
2. Description of the Related Art
A liquid crystal display apparatus includes a liquid crystal display panel and a light source device (see International Publication No. 2007/129419 (hereinafter “Patent Document 1”); and Japanese Laid-Open Patent Publication No. 2009-199871, (hereinafter “Patent Document 2”)). Light source devices of edgelight type have been proposed. An edgelight-type light source device includes a light source section, a light guide plate, and an optical sheet group. The light source section includes a light source(s) and a light source substrate on which the light source(s) is mounted. The light source(s) is disposed opposite a peripheral surface of the light guide plate, and the light guide plate is disposed facing a rear surface of the liquid crystal display panel via the optical sheet group.
At the peripheral surface of the light guide plate, light which is emitted from the light source section enters the interior of the light guide plate. The light which has entered the interior of the light guide plate goes out from a frontal surface of the light guide plate. The light which has gone out from the frontal surface of the light guide plate undergoes diffusion, convergence, etc., as effected by the optical sheet group, to enter the interior of the liquid crystal display panel at the rear surface of the liquid crystal display panel. In other words, the liquid crystal display panel is illuminated by the light source device through the rear surface.
In a liquid crystal display apparatus which is described in Patent Document 1, an opening is made in a frame member that surrounds the liquid crystal display panel. Through this opening, the light source section (being described as a first substrate having LEDs thereon”) is insertable into and detachable from the interior of the frame member. This allows the light source section to be exchanged.
In a liquid crystal display apparatus which is described in Patent Document 2, a light guide plate includes a light guide main body and a lightguiding section which are an integral piece, while a light source section includes light sources, a light source substrate, and a light source holder that holds the light source substrate. A slope with a predetermined taper angle is created in the lightguiding section, and protrusions to define a separation distance (clearance) between the light source and a peripheral surface of the light guide plate are provided on the light source holder. By allowing contact between the light source holder and the slope of the lightguiding section, an improved clearance precision is obtained.
In a liquid crystal display apparatus for use in relatively bright places (e.g., outdoors)(hereinafter referred to a display apparatus for bright places), the displaying region of the liquid crystal display panel is preferably brighter than that in a liquid crystal display apparatus for use in relatively dark places (e.g., indoors)(hereinafter referred to as a display apparatus for dark places). To realize this, a light source device which is used in the display apparatus for bright places needs to have a higher luminance than the luminance of a light source device which is used in the display apparatus for dark places.
In accordance with the liquid crystal display apparatus described in Patent Document 1, a display apparatus for bright places can be provided by inserting a high-luminance light source section through the opening in the frame member, whereas a display apparatus for dark places can be provided by inserting a low-luminance light source section. The higher the luminance of the light source section is, the higher the luminance of the light source device is. However, there is a problem of an increased number of component parts and an increased production cost because no common light source section is being shared between a display apparatus for bright places and a display apparatus for dark places.
In accordance with the liquid crystal display apparatus described in Patent Document 2, a display apparatus for bright places can be obtained when a light source section and a light guide plate with shorter clearance therebetween are used, whereas a display apparatus for dark places can be obtained when a light source section and a light guide plate with longer clearance therebetween are used. The shorter the clearance is, the higher the luminance of the light source device is. However, there is a problem of an increased number of component parts and an increased production cost because no common light source section and light guide plate are being shared between a display apparatus for bright places and a display apparatus for dark places.